CaO(s) reacts with SO2(g) according to the following equations: CaO9(s)+So2(g)--> CaSO3(g).
A 8.85g mixture containing CaO(s) is placed in a 3.00-L container. The container is filled with SO2(g) to a pressure of 749 torr, at 20.0 degree Celsius. After the reaction has gone to completion, the pressure inside the flask is 390 torr, also at 20.0 degree Celsius. What is the mass of CaSO39(s) produced? Assume that only CaO(s) in the mixture reacts with SO2(g).